Multiple bouts of high-intensity interval exercise reverse age-related functional connectivity disruptions without affecting motor learning in older adults

Abstract

Exercise has emerged as an intervention that may mitigate age-related resting state functional connectivity and sensorimotor decline. Here, 42 healthy older adults rested or completed 3 sets of high-intensity interval exercise for a total of 23 min, then immediately practiced an implicit motor task with their non-dominant hand across five separate sessions. Participants completed resting state functional MRI before the first and after the fifth day of practice; they also returned 24-h and 35-days later to assess short- and long-term retention. Independent component analysis of resting state functional MRI revealed increased connectivity in the frontoparietal, the dorsal attentional, and cerebellar networks in the exercise group relative to the rest group. Seed-based analysis showed strengthened connectivity between the limbic system and right cerebellum, and between the right cerebellum and bilateral middle temporal gyri in the exercise group. There was no motor learning advantage for the exercise group. Our data suggest that exercise paired with an implicit motor learning task in older adults can augment resting state functional connectivity without enhancing behaviour beyond that stimulated by skilled motor practice.

Shared brain and genetic architectures between mental health and physical activity

“…Evidence from fMRI studies on physical activity demonstrated the changes in the activity of and functional connectivity between these network hub regions including the hippocampus, parahippocampus, dorsal anterior cingulate cortex (dACC), and ventromedial prefrontal cortex (vmPFC) that primarily subserve executive functions such as working memory, attention, and inhibition [ 15 – 19 ]. At the more system level, a 12-month aerobic walking intervention was found to increase resting-state functional connectivity between subnetworks of DMN, and between subnetworks of SN [ 20 ], whereas connectivity in the CEN was found to increase after multiple sessions of high-intensity interval training [ 21 ]. Interestingly, the intensity of physical exercise appeared to modulate functional connectivity changes in the hub regions of the CEN [ 22 ], as well as in the DMN subsystems acutely and after 3 months of training [ 23 ].…”

Improved cognitive-motor processing speed and decreased functional connectivity after high intensity aerobic exercise in individuals with chronic stroke

“…The data in this manuscript come from a large study on the impact of exercise on behaviour, brain function, and physiology in individuals with stroke. The data reported here are a subset of the larger study (Greeley et al ., 2021, 2023; Neva et al ., 2022).…”

“…The serial targeting task was employed as the motor training task (Brodie et al ., 2014; Mang et al ., 2016; Greeley et al ., 2021). Participants used their paretic arm to control a frictionless manipulandum to move a cursor between a start position and an end target projected by the Kinarm end-point robot (Kinarm, Kingston, ON, Canada).…”

“…Aerobic exercise can alter patterns of brain activity, including resting-state functional connectivity between brain networks as measured by functional magnetic resonance imaging (fMRI) (Weng et al ., 2017; Greeley et al ., 2021), and is known to improve cognitive function in healthy older adults (Barnes, 2015), and in individuals with stroke (Zheng et al ., 2016). High intensity aerobic exercise in particular can also improve motor skill acquisition in neurologically intact people (Skriver et al ., 2014; Stavrinos & Coxon, 2017; Dal Maso et al ., 2018; Kendall et al ., 2020), and individuals with chronic stroke (Nepveu et al ., 2017).…”

Shared brain and genetic architectures between mental health and physical activity

“…Furthermore, fMRI studies of physical activity have reported changes in activity of and functional connectivity between brain areas including hippocampus, parahippocampus, dorsal anterior cingulate cortex, and ventromedial prefrontal cortex that primarily subserve executive functions such as memory, attention, and inhibition 28–32 . At the network level, a 12-month aerobic walking intervention was found to increase resting-state functional connectivity between DMN nodes 33 , whereas connectivity in the CEN was found to increase after multiple sessions of high intensity interval training 34 . Interestingly, the intensity of physical exercise appeared to modulate functional connectivity changes in the hub regions of the CEN 35 , as well as in the DMN subsystems acutely and after 3 months of training 36 .…”